Stiff Pen Shell (Atrina rigida)

Firm Pen Shell (Atrina rigida) The firm pen shell, or inflexible pen shell, is one of the few types of pen shells. These mollusks have a long, triangular, or wedge-molded shell and append to rocks or shells in sandy, shallow sea bottoms. Depiction Firm pen shells can be up to 12 long and 6.5 wide. They are an earthy colored or purplish-earthy colored shading and have at least 15 transmitting ribs that fan out over the shell. They may likewise have erect, rounded spines. Pen shells may create dark pearls. Order Realm: AnimaliaPhylum: MolluscaClass: BivalviaOrder: PterioidaFamily: PinnidaeGenus: AtrinaSpecies: rigida Living space and Distribution Solid pen shells live in hotter water from North Carolina to Florida, and furthermore in the Bahamas and West Indies. They are found on sandy bottoms in shallow water. They append with their byssal strings, pointed end down. Taking care of Pen shells are channel feeders and eat little particles going through the water. Protection and Human Uses Pen shells have a scallop-like adductor muscle (the muscle that opens and shuts the shells) and are palatable. They likewise produce dark pearls which might be utilized in adornments. Pen shells in the (Mediterranean pen shells) were gathered for their byssal strings, which were woven into a costly material. Sources Gofas, S. 2011. Pinnidae. World Register of Marine Species (Online) Accessed on May 24, 2011Meinkoth, N.A. 1981. National Audubon Society Field Guide to North American Seashore Creatures. Alfred A. Knopf, New YorkScott, S. 2011. Pen Shells Provided Ancients Byssal Threads for Fine Sea Silk (Online) Accessed May 24, 2011